Document 0421
 DOCN  M9590421
 TI    cis-acting regulatory elements in the bovine immunodeficiency virus long
       terminal repeat.
 DT    9509
 AU    Fong SE; Pallansch LA; Mikovits JA; Lackman-Smith CS; Ruscetti FW; Gonda
       MA; Laboratory of Cell and Molecular Structure, Program Resources,;
       Inc./DynCorp, Frederick, Maryland, USA.
 SO    Virology. 1995 Jun 1;209(2):604-14. Unique Identifier : AIDSLINE
       MED/95297161
 AB    Functional cis-acting regulatory elements in the bovine immunodeficiency
       virus (BIV) long terminal repeat (LTR) were identified by deletion
       mapping and nuclear protein gel shift analysis using three
       BIV-infectible cell lines, Cf2Th, BLAC-20, and EREp. Deletion mapping
       studies indicated that putative NF-kappa B, GRE, AP-4, AP-1, CAAT, and
       ATF/CRE transcription factor elements positively contribute to
       LTR-directed gene expression in each cell line both in the presence and
       absence of the viral transactivator Tat. Sp1 and overlapping AP-3 and
       retroviral core enhancer elements had variable effects on LTR-directed
       gene expression depending on cell type and presence or absence of Tat.
       In addition, a sequence spanning the LTR U5 region and the untranslated
       viral leader was strongly repressive in all cell lines. Tat
       transactivated the LTR 25-fold over basal levels in a TAR-dependent
       manner in Cf2Th cells. In contrast, Tat transactivated the LTR only
       2.5-fold over basal levels in EREp and BLAC-20 cells in a
       TAR-independent manner. Probes for putative NF-kappa B, GRE, Sp1, AP-4,
       AP-1, overlapping AP-3 and retroviral core enhancer, and juxtaposed CAAT
       and ATF-CRE elements specifically bound nuclear proteins from these
       three cell lines and HeLa cells, with the stoichiometry of binding being
       cell-type dependent. Probes for AP-4, AP-1, and juxtaposed CAAT and
       ATF/CRE elements exhibited greater protein binding with extracts from
       virally infected cells than with extracts from uninfected cells,
       suggesting that viral infection can modulate nuclear factor binding. The
       present studies indicate that several transcription factor elements in
       the BIV LTR have functional roles and that cell type can strongly
       determine the role they play in gene expression.
 DE    Animal  Base Sequence  Binding Sites  Cattle  Cell Line  Cell
       Nucleus/METABOLISM  Consensus Sequence  Dogs  DNA,
       Viral/CHEMISTRY/*GENETICS/METABOLISM  Immunodeficiency Virus,
       Bovine/*GENETICS/PHYSIOLOGY  Molecular Sequence Data  Nuclear
       Proteins/*METABOLISM  Rabbits  *Regulatory Sequences, Nucleic Acid
       *Repetitive Sequences, Nucleic Acid  Restriction Mapping  Sequence
       Deletion  Transcription Factors/*METABOLISM  Virus Replication  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).